DE112018003699T5 - Sensor calibration device and sensor calibration program - Google Patents

Abstract

A sensor calibration device for calibrating an output of a position sensor (41 to 43) for detecting a position of a vehicle includes a measurement value acquisition section (61) that obtains a measurement value of the position of the vehicle based on the output of the position sensor, a vehicle speed acquisition section (62), the vehicle speed information, which indicate a running speed of the vehicle, a map information acquisition section (64) which acquires map information on a road on which the vehicle is traveling, and a calibration value setting section (66) which sets a calibration value applied to the measured value cause a calculated position of the vehicle calculated based on the vehicle speed information and the measured value to approach a reference position specified in the map information.

Description

CROSS REFERENCE TO RELATED APPLICATIONS:

This registration is based on the one filed on July 18, 2017 Japanese patent application number 2017-139339 and on June 19, 2018 Japanese patent application number 2018-116304 , the disclosures of which are incorporated by reference.

TECHNICAL AREA

The disclosure of the present specification relates to a sensor calibration device and a sensor calibration program for calibrating an output of a position sensor for detecting a position of a vehicle.

background

As some types of position sensors for measuring a position of a vehicle, an acceleration sensor, an angular velocity sensor, and the like are known, for example, as disclosed in Patent Document 1. In the position sensors of the above types, an output may change due to, for example, a change in an ambient temperature, an individual difference, or the like. Accordingly, a correction device as disclosed in Patent Document 1 calibrates the output of the position sensor based on the measured ambient temperature of the position sensor and the temperature-specifying data stored in advance.

PRIOR ART LITERATURE

PATENT LITERATURE

Patent document 1: JP 2009-25012 A

OVERVIEW OF THE INVENTION

In recent years, various types of information can be obtained to a large extent for driving a driver through a vehicle. The inventors of the present disclosure have repeatedly examined whether the output of the position sensor can be calibrated using such information that can be obtained by the vehicle.

It is an object of the present disclosure to provide a sensor calibration device and a sensor calibration program that can calibrate a position sensor using information that is different from conventional information.

According to an aspect of the present disclosure, a sensor calibration device for calibrating an output of a vehicle position detection device includes a measurement value acquisition section that obtains a measurement of the vehicle position based on the output of the position sensor, a vehicle speed acquisition section that obtains vehicle speed information, a travel speed of the vehicle specify a map information acquisition section that acquires map information on a road on which the vehicle is running, and a calibration value setting section that sets a calibration value that is applied to the measurement value by a calculated position of the vehicle based on the Vehicle speed information and the measured value is calculated to cause to approach a reference position, which is specified in the map information.

According to an aspect of the present disclosure, a sensor calibration program for calibrating an output of a position sensor for detecting a position of a vehicle causes at least one processor to, as a measurement value acquisition section that obtains a measurement value of the position of the vehicle based on the output of the position sensor, a vehicle speed acquisition section, the vehicle speed information that indicate a running speed of the vehicle, a map information acquisition section that acquires map information of a road on which the vehicle is running, and a calibration value setting section that sets a calibration value that is applied to the measurement value to calculate a calculated position of the vehicle, that is calculated based on the vehicle speed information and the measured value, to cause it to approach a reference position specified in the map information.

As in these aspects, the measured value of the position sensor and the vehicle speed information are combined with each other, whereby the calculated position can be obtained based on the measured value of the position sensor. If the calibration value is set so that the calculated position approaches the reference position indicated in the map information, the position sensor can be calibrated using the map information. According to the above configuration, the position sensor can be calibrated using information different from the conventional information.

According to an aspect of the present disclosure, a sensor calibration device for calibrating an output of a position sensor for detecting a position of a vehicle includes a measured value acquisition section that obtains a measured value of the position of the vehicle based on the output of the position sensor, a vehicle speed acquisition section that acquires vehicle speed information that a driving speed of the vehicle Vehicle, a position identification section that identifies a position determination position of the vehicle based on a position determination signal received from a position determination satellite, and a calibration value setting section that sets a calibration value applied to the measurement value to cause a calculated position of the vehicle , which is calculated based on the vehicle speed information and the measured value, the position determination position approaches n identified by the position identification section.

According to an aspect of the present disclosure, a sensor calibration program for calibrating an output of a position sensor for detecting a position of a vehicle causes at least one processor to, as a measurement value acquisition section that obtains a measurement value of the position of the vehicle based on the output of the position sensor, a vehicle speed acquisition section, the vehicle speed information that indicate a running speed of the vehicle, a position identification section that identifies a position determination position of the vehicle based on a position determination signal received from a satellite, and a calibration value setting section that sets a calibration value that is applied to the measurement value so as to cause a calculated position of the vehicle, which is calculated based on the vehicle speed information and the measured value, to change the position ns determination position approaches, which is identified by the position identification section.

In this aspect, the calibration value of the position sensor is set so that the calculated position based on the vehicle speed information and the measured value approaches the position determination position that is identified based on the position determination signal. As described above, the position sensor can be calibrated using the positioning signal received from the satellite and different from the conventional information.

According to an aspect of the present disclosure, a sensor calibration device for calibrating an output of a position sensor for detecting a displacement of a vehicle includes a measurement value acquisition section that obtains a measurement value of the displacement of the vehicle based on the output of the position sensor; acquires a vehicle speed obtaining section of the vehicle speed information indicating a running speed of the vehicle; an altitude information acquisition section that acquires altitude information about a road on which the vehicle is traveling; and a calibration value setting section that one Sets a calibration value applied to the measurement value to cause a calculated position of the vehicle calculated based on the vehicle speed information and the measurement value to approach a reference position indicated in the altitude information.

According to an aspect of the present disclosure, a sensor calibration program for calibrating an output of a position sensor for detecting an offset of a vehicle causes at least one processor to acquire, as a measurement value acquisition section that obtains a measurement value of an offset of the vehicle based on the output of the position sensor, a vehicle speed acquisition section of the vehicle speed information that indicate a running speed of the vehicle, an altitude information acquisition section that acquires altitude information about a road on which the vehicle is running, and a calibration value setting section that sets a calibration value that is applied to the measurement value to cause a calculated position of the vehicle, which is calculated based on the vehicle speed information and the measured value, approaches a reference position that is in the altitude information format ions is specified.

In these aspects, the measured value of the position sensor and the vehicle speed information are combined with each other, whereby the calculated position of the altitude can be calculated based on the measured value of the offset of the vehicle. If the calibration value is set so that the calculated position approaches the reference position indicated by the altitude information, the altitude sensor can be calibrated using the altitude information. Accordingly, the position sensor can be calculated using the information that is different from the conventional information.

Figure list

• 1 ein Blockschaltbild, das ein Gesamtbild eines Systems zeigt, das an einem Fahrzeug montiert ist, das eine Anzeigesteuervorrichtung der vorliegenden Offenbarung beinhaltet, gemäß einer ersten Ausführungsform;
• 2A ein Diagramm, das eine Verarbeitung zum Abgleichen eines berechneten Fahrtlocus mit einem Fahrtlocus basierend auf Kartendaten in einer visualisierten Weise, um einen Kalibrierungskoeffizienten (vor der Kalibrierung) festzulegen, zeigt;
• 2B ein Diagramm, das eine Verarbeitung zum Abgleichen des berechneten Fahrtlocus mit dem Fahrtlocus basierend auf den Kartendaten, um den Kalibrierungskoeffizienten (nach der Kalibrierung) festzulegen, zeigt;
• 3 ein Ablaufdiagramm, das Details einer Aktualisierungsverarbeitung des Kalibrierungskoeffizienten zeigt;
• 4 ein Ablaufdiagramm, das Details einer Datenauswahlverarbeitung zeigt;
• 5 ein Ablaufdiagramm, das Details einer Aktualisierungsverarbeitung gemäß einer zweiten Ausführungsform zeigt;
• 6 ein Blockschaltbild, das ein Gesamtbild eines Systems zeigt, das an einem Fahrzeug montiert ist, das eine Anzeigesteuervorrichtung beinhaltet, gemäß einer dritten Ausführungsform;
• 7 ein Diagramm, das eine Verarbeitung zum Abgleichen einer berechneten Eigenfahrzeughöhenlage mit einer Eigenfahrzeughöhenlage basierend auf den Kartendaten in einer visualisierten Weise, um den Kalibrierungskoeffizienten festzulegen, zeigt;
• 8 ein Ablaufdiagramm, das Details einer Aktualisierungsverarbeitung gemäß der dritten Ausführungsform zeigt;
• 9 ein Ablaufdiagramm, das Details einer Datenauswahlverarbeitung zeigt;
• 10 ein Ablaufdiagramm, das eine Datenauswahlverarbeitung gemäß Modifikation 1 zeigt;
• 11 ein Ablaufdiagramm, das eine Datenverarbeitung gemäß Modifikation 2 zeigt;
• 12 ein Ablaufdiagramm, das eine Datenauswahlverarbeitung gemäß Modifikation 3 zeigt.

The foregoing, as well as other objects, features, and advantages of the present disclosure, will become more apparent from the following detailed description when taken in conjunction with the drawings. Show it:

• 1 3 is a block diagram showing an overall image of a system mounted on a vehicle that includes a display control device of the present disclosure according to a first embodiment;
• 2A a diagram showing processing for matching a calculated travel locus with a travel locus based on map data in a visualized manner to set a calibration coefficient (before calibration);
• 2 B a diagram showing processing for matching the calculated travel locus with the travel locus based on the map data to set the calibration coefficient (after calibration);
• 3rd a flowchart showing details of update processing of the calibration coefficient;
• 4th a flowchart showing details of data selection processing;
• 5 a flowchart showing details of update processing according to a second embodiment;
• 6 15 is a block diagram showing an overall image of a system mounted on a vehicle including a display control device according to a third embodiment;
• 7 4 is a diagram showing processing for matching a calculated own vehicle height with a own vehicle height based on the map data in a visualized manner to set the calibration coefficient;
• 8th a flowchart showing details of update processing according to the third embodiment;
• 9 a flowchart showing details of data selection processing;
• 10th a flowchart showing data selection processing according to modification 1;
• 11 a flowchart showing data processing according to modification 2;
• 12th a flowchart showing data selection processing according to modification 3.

Description of the embodiments

Several embodiments of the present disclosure are described below with reference to the drawings. The same reference numerals are assigned to the corresponding components in each embodiment, and thus duplicate description can be omitted. If only part of the configuration is described in each embodiment, the configuration of the other embodiments described above can be applied to other parts of the configuration. Further, not only the combinations of the configurations explicitly shown in the description of the respective embodiments, but also the configurations of the multiple embodiments can be partially combined even if the combinations are not explicitly shown if there is no problem with the combination itself . Unspecified combinations of configurations in the several Embodiments are described, and the modification examples are also disclosed in the description below.

(First embodiment)

In a first embodiment of the present disclosure, which is in 1 A function of a sensor calibration device is shown by a display control device 100 realized. The display control device 100 is one of several electronic control units that are mounted on a vehicle. The display control device 100 is electrically provided with a plurality of display devices such as a HUD device or field of view display device and an instrument cluster and controls the display of these devices. The display control device 100 is electrically direct or indirect with an in-vehicle LAN 50 , a map database (hereinafter referred to as "map DB") 30th , a GNSS receiver 20th , a sensor section 40 and the like in addition to the display devices such as the HUD device 10th connected.

The HUD (Head up Display, Field of View) display is a device that takes a virtual image VI in front of an occupant of a vehicle, such as a driver of the vehicle. The virtual picture VI is in a room in front of the vehicle and at a position of, for example, 10 to 20th m trained from an eye point of the driver. The virtual picture VI is superimposed on a road surface and other vehicles in a driver 's view, making it an indication of augmented reality (hereinafter referred to as AR designated) works. For example, warning information, route information and the like are made available to the driver by the virtual image VI presents.

The HUD device 10th includes a projector 11 , a catoptric system 12th and an actuator 13 as a configuration for displaying the virtual image VI . The projector 11 emits a light from a display image, called the virtual image VI is trained towards the catoptric system. The catoptric system 12th projects the light of the display image emanating from the projector 11 occurs on a projection region PA a windshield WS . The light that shines on the windshield S is projected towards the eye point side over the projection region PA reflected and perceived by the driver. The actuator 13 changes a position of the catoptric system, thereby making a projection position of the light of the display image in the projection region PA changes. The HUD device described above 10th changes a display position of the virtual image up and down in the driver's view using drawing control of the display image by the projector 11 is drawn, and / or a position control of the catoptric system 12th through the actuator 13 .

The in-vehicle LAN (Local Area Network) 50 is connected to a large number of electronic control units and a large number of vehicle-mounted sensors. Different types of information are sent from electronic control units and the vehicle-mounted sensors to the in-vehicle LAN 50 spent. Vehicle speed information indicating a running speed of the vehicle, driving force information indicating a driving force of the vehicle, and the like are sent to the in-vehicle LAN, for example 50 spent.

The map DB 30th mainly includes a large capacity storage medium for storing a large number of pieces of map data. Map data includes information about a curvature value, a gradient value and a section length for each street, as well as information about non-temporary traffic regulations such as a speed limit for the street and a one-way street regulation. Furthermore, the map data includes coordinate information indicating longitude, latitude, and altitude at multiple points on the road as information indicating the position of the road in three dimensions. Each value of the longitude, the latitude and the altitude or the altitude which is included in the coordinate information is a value which is measured by high-precision position determination in order to enable autonomous driving.

The GNSS (Global Navigation Satellite System) receiver 20th receives positioning signals from multiple positioning satellites. The GNSS receiver 20th sequentially outputs the received positioning signals to the display control device 100 out. The GNSS receiver 20th can receive the positioning signals from respective positioning satellites from at least one satellite positioning system from satellite positioning systems such as GPS, GLONAS, Galileo, IRNSS, QZSS and Beidou.

The sensor section 40 is a motion sensor for detecting the position of the vehicle. The sensor section 40 is fixed at an arbitrary position of the vehicle and measures an inclination, a rotation and a yaw and the like that are generated in the vehicle. The sensor section 40 has several gyro sensors 41 to 43 for measuring changes in the position of the center of gravity around a yaw axis, an inclination axis and an axis of rotation of the vehicle, that is, changes in position.

The gyro sensors 41 to 43 are, for example, sensors that detect an angular velocity as a voltage value. Each of the gyro sensors 41 to 43 is provided in a different position in order to be able to measure a magnitude of an angular velocity that is generated about each axis of an X axis, a Y axis and a Z axis that are orthogonal to one another. Each of the gyro sensors 41 to 43 measures a measured value around each axis and sequentially outputs the measured value to the display control device 100 out. The orientations of the three axes that are in the sensor section 40 can be inclined with respect to the yaw axis, the inclination axis and the roll axis of the vehicle.

The display control device 100 includes a control circuit 60 , a permanent memory 60a , an input / output interface and the like. The control circuit 60 mainly includes a CPU (central processing unit), a GPU (graphics processing unit), RAM (random access memory, random access memory) and the like. The permanent memory 60a stores different programs through the control circuit 60 are to be carried out. In particular, there are a display control program for controlling the display of the virtual image VI , a sensor calibration program for calibrating the output of the gyro sensors 41 to 43 and the like in the ROM 60a saved.

The control circuit 60 configures several functional blocks by executing different programs in the ROM 60a are saved. In particular, the control circuit includes 60 a display control section 71 , a location calculation section 72 and an actuator control section 73 as functional blocks based on the display control program. The control circuit 60 includes a measurement acquisition section 61 , a vehicle speed acquisition section 62 , an acceleration acquisition section 63 , a map information acquisition section 64 , a position identification section 65 and a calibration value setting section 66 as functional blocks based on the sensor calibration program m.

The display control section 71 controls the display of the virtual image VI through the HUD device 10th . The display control section 71 chooses a virtual image VI , which is to be used for information presentation, based on different information that is provided by the in-vehicle LAN 50 can be obtained. The display control section 171 draws image data to display the selected virtual image VI and sequentially outputs the rendered image data to the projector 11 out. With the display control device of the display control section 71 described above, a light of a display image based on the image data from the projector 11 projected to the catoptric system.

The location calculation section 72 calculates an inclination angle θ _p , a roll angle θ _r , a yaw angle θ _y as the position information of the vehicle based on the outputs of the gyro sensors 41 to 43 by the measurement acquisition section 61 can be obtained. A temperature drift occurs in the values of the gyro sensors 41 to 43 as an error caused by a change in an ambient temperature at which the sensor section 40 installed. Furthermore, when an angle is calculated according to the angular velocity, an error (time drift) associated with temporal integration also occurs. The position calculation section calibrates to correct error factors of the temperature drift and the time drift 72 the measured values θ _{p_sens} , θ _{r_sens} and θ _{y_sens} , the raw outputs of the gyro sensors 41 to 43 are using a calibration expression shown in Expression 1 below. Calibration coefficients a _p , b _p , a _r , b _r , a _y and b _y in the calibration expression are values by the calibration value setting section 66 be determined.

$$\{\begin{array}{c}{\theta }_p=a_p\cdot {\theta }_{p\_sens}+b_p\\ {\theta }_r=a_r\cdot {\theta }_{r\_sens}+b_r\\ {\theta }_y=a_y\cdot {\theta }_{y\_sens}+b_y\end{array}$$

The actuator control section 73 operates the actuator 13 based on the position information of the vehicle by the position calculation section 72 are calculated, and moves a projection position of the light of the display image in the projection region PA in the vertical direction. Even if yourself the position of the vehicle changes, the actuator control section controls 73 the location of the catoptric system 12th with the actuator 13 so that the deviation of the superimposed position of the virtual image VI caused by the change in position of the vehicle is corrected. According to the control of the actuator control section 73 can the virtual image VI be maintained in a state where the virtual image VI is correctly superimposed on an object in the driver's view.

In addition to the position control by the actuator control section 73 or instead of the position control, the display control section 71 a controller for changing an arrival position of the light on the display image by the projector 11 to the catoptric system 12th is projected. Even in the drawing control of the display control section 71 As described above, the virtual image VI be maintained in a state in which it is correctly superimposed on the object in the driver's view.

The measurement acquisition section 61 obtains the angular velocities around the inclination axis, the roll axis and the yaw axis of the vehicle by the respective gyro sensors 41 to 43 are detected by the sensor section 40 . If the three axes through the sensor section 40 are defined with respect to the three axes of the vehicle, the measurement value acquisition section corrects 61 the outputs of the respective gyro sensors 41 to 43 to angular velocities around the three axes of the vehicle through coordinate transformation. The measurement acquisition section 61 obtains the inclination angle θ _{p_sens} , the roll angle θ _{r_sens} and the yaw angle θ _{y_sens of} the vehicle by integrating the angular velocity around each axis over time.

The vehicle speed acquisition section 62 obtains vehicle speed information indicating the running speed of the vehicle, the vehicle speed information being sent to the in-vehicle LAN 50 be issued. The acceleration acquisition section 63 acquires the driving force information indicating the driving force of the vehicle, the driving force information to the in-vehicle LAN 50 be issued. The acceleration acquisition section 63 obtains the acceleration information indicating the acceleration of the vehicle based on the driving force information and specification information such as weight of the vehicle, outer circumference of a tire, a gear ratio of a drive system, and the like.

The map information acquisition section 64 obtains three-dimensional map data including information about latitude, longitude and altitude for the street on which the vehicle is traveling from the map DB 30th . In particular, the map information acquisition section requests 64 the map DB 30th to provide the map data around the current position of the vehicle and the map data including the road on which the vehicle was traveling. The map information acquisition section 64 can obtain the map data around the vehicle through, for example, a communication network.

The position identification section 65 obtains the positioning signals from satellites by the GNSS receiver 20th be received. The position identification section 65 identifies the current position determination position of the vehicle based on the position determination signals. The vehicle speed acquisition section 62 and the acceleration acquisition section 63 may obtain the vehicle speed information and the acceleration information each based on the transition of the position determination position by the position identification section 65 is identified.

The calibration value setting section 66 sets a calibration coefficient (see Expression 1) to be applied to the measurement value by the measurement value acquisition section 61 is obtained. In particular, the calibration value setting section calculates 66 a locomotive RPc of the vehicle (cf. 2A and 2 B) using the coordinate calculation expression shown in Expression 2 below. The driving locomotive RPc is a three-dimensional figure in which coordinates of the calculated position, which is calculated based on the vehicle speed information and the measured values, are connected in series.

In the following coordinate calculation expression, v is a running speed of the vehicle, which is indicated by the vehicle speed information. Further, (x _i , y _i , z _i ) are the calculated coordinate position of the own vehicle at a time i and (x _{y + 1} , y _{i + 1} , z _{i + 1} ) are coordinates of the calculated position of the own vehicle at a time i + 1. Furthermore, the inclination angle θ _p , the roll angle θ _r and the yaw angle θ _y attitude angle are based on the pre-calibration measurement values θ _p-sens , θ _{r_sens} , θ _{y_sens} or a calibration _expression in which temporary calibration _coefficients are defined. $$\left[\begin{array}{c}{x}_{i+1}\\ y_{i+1}\\ {\mathrm{e.g.}}_{i+1}\end{array}\right]=v\left[\begin{array}{c}-\text{sin}{\theta }_y\text{sin}{\theta }_p\text{sin}{\theta }_r+\text{cos}{\theta }_r\text{cos}{\theta }_y-\text{sin}{\theta }_y\text{cos}{\theta }_p+\text{sin}{\theta }_y\text{sin}{\theta }_p\text{cos}{\theta }_r+\text{sin}{\theta }_r\text{cos}{\theta }_y\\ \text{cos}{\theta }_y\text{sin}{\theta }_p\text{sin}{\theta }_r+\text{cos}{\theta }_r\text{sin}{\theta }_y+\text{cos}{\theta }_y\text{cos}{\theta }_p-\text{cos}{\theta }_y\text{sin}{\theta }_p\text{cos}{\theta }_t+\text{sin}{\theta }_r\text{sin}{\theta }_y\\ -\text{cos}{\theta }_p\text{sin}{\theta }_r+\text{sin}{\theta }_p+\text{cos}{\theta }_p\text{cos}{\theta }_r\end{array}\right]+\left[\begin{array}{c}{x}_i\\ y_i\\ {\mathrm{e.g.}}_i\end{array}\right]$$

The calibration value setting section 66 sets a locomotive RPm (see. 2A and 2 B) that the vehicle is estimated to have driven on based on road shape information shown in the map data. The calibration value setting section 66 assumes the driving locus RPm is a true value based on the map data. Then the calibration value setting section calculates 66 a calibration coefficient such that the calculated driving locus RPc the driving locomotive RPm approximates (overlaps) based on the map data, that is, such that an error of the driving locus RPc regarding the locomotive RPm is minimized.

In particular, the calibration value setting section sets 66 Coordinates to the locomotive RPc each corresponding to a large number of coordinates on the locomotive RPm firmly. The calibration value setting section 66 sets a pair of coordinate information pieces, which are estimated to indicate the position of the vehicle at the same time, from each of the driving loci RPm and RPc firmly. The calibration value setting section 66 searches for a minimum value of an objective function, as shown in Expression 3 below. In the objective function there is an error norm between coordinates (x ^ _t , y ^ _t , z ^ _t ) a reference position on the locomotive RPm and coordinates (x _t , y _t , z _t ) of the calculated position on the driving locus RPc calculated for the coordinates of the respective combined pairs. The calibration value setting section sets the calibration coefficient so that a sum of the error norms becomes minimal. The calibration value setting section 66 searches for a calibration coefficient by an iterative calculation using a gradient method. $$\text{min}\left({\displaystyle \sum _{t=0}^n\sqrt{{\left({\widehat{x}}_t-x_t\right)}^{\mathrm{2nd}}+{\left({\widehat{y}}_t-y_t\right)}^{\mathrm{2nd}}+{\left({\widehat{\mathrm{e.g.}}}_t-{\mathrm{e.g.}}_t\right)}^{\mathrm{2nd}}}}\right)$$

The calibration value setting section 66 determines a driving state of the vehicle and determines the calibration coefficient with the exclusion of the measured value, which is measured in a specific driving state. In particular, the measured values by the respective gyro sensors 41 to 43 during acceleration and deceleration of the vehicle are measured, excluded from object data used to set the calibration coefficient. Furthermore, the measured values by the respective gyro sensors 41 to 43 during a period when the vehicle passes the road surface unevenness are also excluded from the object data used to set the calibration coefficient.

The display control device 100 , which has been described so far, continuously carries out update processing for updating the calibration coefficient. The following are details of the processing for updating the calibration coefficient based on 3rd and 4th regarding 1 described. In the 3rd Update processing is shown by the control circuit 60 started based on the fact that the vehicle is ready to drive. The update processing is repeated by the control circuit 60 until a power supply or ignition of the vehicle is switched off.

At S101 the measured values are based on the outputs of the respective gyro sensors 41 to 43 the vehicle speed information is obtained and the processing moves along S102 away. At S102 data to be used to set the calibration coefficient will be used by the at S101 obtained measured values selected. In other words, at S102 the measurements that can cause a large error in the calibration coefficients are excluded from an object to be used by the data selection processing described in 4th is shown.

At S121 In the data selection processing, acceleration information is obtained during the period or the time when the measured value is measured. Then it is determined whether an absolute value of the acceleration occurring in the vehicle is a limit value A exceeds. Is at S121 determines that the absolute value of the acceleration is equal to or less than the limit A processing is included S123 away. On the other hand, if it is determined that the absolute value of the acceleration is the limit A processing is included S121 away. At S122 becomes the measured value during the period in which the absolute value of the acceleration exceeds the limit A exceeds, excluded from the object used to set the calibration coefficient, and the processing goes along S123 away. As described above, data during acceleration and deceleration are excluded from the object to be used.

In S131 a difference value of the coordinates of the calculated position is calculated in time series. The difference value can be, for example, a value (| x _t -x _t-1 |) for one of the coordinates x, y and z and can be a value of a spatial distance between the two coordinates. It should be noted that x _t is a value of the calculated position at a time t and x _{t-1 is} a value of the calculated position at a time t-1.

Then it is determined whether an absolute value of the difference value of the coordinates is a limit value B exceeds. Is at S123 determines that the absolute value of the difference value is equal to or less than the limit value B processing is included S125 away. On the other hand, if at S123 it is determined that the absolute value of the difference value is the limit B processing is included S124 away. At S124 becomes the measurement value in a period in which the absolute value of the difference value is the limit value B exceeds, excluded from the object to be used to set the calibration coefficient, and processing goes along S125 away. As described above, when the position of the vehicle suddenly changes due to passage of irregularities on the road surface or the like, data is excluded from the object to be used.

At S125 becomes a variance value of the coordinates of the calculated position in a specified period (e.g. several seconds) and it is determined whether the variance value is the limit C. exceeds. Is at S125 determines that the variance value is equal to or less than a limit C. processing is reversed S103 the update processing (main processing). On the other hand, if at S125 it is determined that the variance value is the limit C. processing is included S126 away. At S126 becomes the measurement in a period in which the variance value is the limit C. exceeds, excluded from the object used to set the calibration coefficient, and processing returns S103 the main processing back in 3rd is shown. As described above, the data is excluded from the object to be used in a period in which the position of the vehicle has changed due to some reason that does not appear in the map data.

At S103 becomes a pre-calibration locomotive RPc calculated by the above coordinate calculation expression (see Expression 2) and the processing moves along S104 away. At S104 the card data from the card DB 30th read out and the driving locus RPm of the vehicle is determined. Points corresponding to the individual coordinates on the locomotive RPm , that is, coordinates closest to the individual coordinates are derived from a coordinate group of the calculated positions at S103 be calculated, selected and the processing goes along S105 away.

In S105 the respective calibration coefficients of the calibration printout (expression 1) are calculated in such a way that an error between the calculated position and the reference position, that with S104 is linked, minimized, and the update processing is completed once.

In the first embodiment described so far, the calculated position is obtained by combining the measurement value based on the outputs of the gyro sensors 41 to 43 and the vehicle speed information. If the calibration coefficient is set so that the calculated position approximates the reference position shown in the map data, the sensor section can 40 be calibrated using the map data. As a result, the gyro sensors can be unlike the prior art 41 to 43 be calibrated using the map data.

According to the above configuration, the accuracy of the position measurement of the vehicle by the gyro sensors 41 to 43 improved. Accordingly, the display control section 71 and the actuator control section 73 the virtual image VI move with high accuracy according to the change in the position of the vehicle. Accordingly, the display control device 100 exactly the virtual image VI overlay the object in the driver's view.

The accuracy of the calibration can also be improved by improving the accuracy of the map data. Furthermore, additional components for calibration, such as a temperature sensor, are not required, as a result of which the costs of the system or the effort for the system can be reduced.

Furthermore, the sensor section 40 configured according to the first embodiment to measure the angular velocity around the three axes and finally the attitude angle. In such a configuration that the three-axis sensor section 40 is used, even if the three-dimensional coordinates are shown in the map data, the measured values can be calibrated around each axis.

In the first embodiment, a point corresponding to the coordinates of the reference position indicated by the map data is selected from the coordinate group of the plurality of calculated positions. As described above, the number of coordinates included in the map data is smaller than the number of coordinates calculated as the calculated position. Accordingly, according to the processing for linking the coordinates of the calculated position with the coordinates of the reference position, the display control device can 100 calculate the calibration coefficient with high accuracy by effectively using the available data.

Furthermore, the calibration value setting section calculates 66 according to the first embodiment, the calibration coefficients, so that the sum of the error norms of the respective coordinates of the respective locomotive of the respective locomotive RPM and RPC becomes minimal. With the calculation processing described above, the calculation load for searching for the calibration coefficient can be reduced while ensuring the accuracy of the calibration coefficient.

The measured values of the gyro sensors 41 to 43 during the period in which the position of the center of gravity of the vehicle is changed are values including the movement of the vehicle that are not included in the map data. Accordingly, the measured values during acceleration and deceleration, which are accompanied by a change in the position of the center of gravity, are excluded from the object which is used to set the calibration coefficient. In particular, the value of the acceleration of the vehicle is obtained as the acceleration information, and the measurement value in the period for which it is estimated that the acceleration state or the deceleration state is present is excluded from the calculation of the calibration coefficient. According to the above configuration, the accuracy of the calibration coefficient calculated using the map data can be maintained at a high level.

Furthermore, irregularities caused, for example, by aging of the road surface, patchwork and the like are not shown in the map data. Accordingly, the measured value at a time of passing the road surface irregularities is a value including a movement that is not included in the map data. For this reason, according to the first embodiment, the measurement value in the period during which the vehicle passes the irregularity in the road surface is excluded from the object used to set the calibration coefficient. In particular, a difference value over time with respect to the coordinates of the calculated position is monitored and the measured value in the period in which a change range of the coordinates exceeds the limit value B exceeds, is excluded from the calculation of the calibration coefficient. According to the above configuration, the accuracy of the calibration coefficient calculated using the map data can be maintained at a high level.

Furthermore, according to the first embodiment, the variance value of the calculated position in the specific period is calculated and the measurement value in the period in which the variance value is the limit value C. is not used to calculate the calibration coefficient. As described above, by using the selection based on the variance value as the position change filter, the measurement value in the period in which a large position change occurs due to a factor that is not included in the map data can be excluded from the calculation of the calibration coefficient. Accordingly, the accuracy of the calibration coefficients can be maintained at a high level.

In the first embodiment, the map data corresponds to “map information”, the calibration coefficient corresponds to a “calibration value”, the gyro sensors 41 to 43 correspond to a "position sensor", the control circuit 60 corresponds to a "processor" and the display control device 100 corresponds to a "sensor calibration device".

(Second embodiment)

When setting a calibration coefficient according to a second embodiment, three-dimensional coordinates indicated by a position determination signal are used as a reference position instead of coordinates specified in the map data. A Calibration value setting section 64 who in 1 is shown, calculates a driving locus RPc (see. 2A and 2 B) of a vehicle using a coordinate calculation expression (see Expression 2) similar to that in the first embodiment. On the other hand, the calibration value setting section sets 66 according to the second embodiment, a locomotive RPm (see. 2A and 2 B) for which it is estimated that the vehicle has driven thereon by processing for connecting position determination positions by a position identification section 65 be identified in time series. The calibration setting section 66 assumes the driving locus RPm is a true value based on a positioning signal and calculates a calibration coefficient so that a calculated driving locus RPc three-dimensional with the driving locomotive RPm based on the position determination signal overlaps, in other words, so that an error of the calculated position with respect to the position determination position is eliminated.

In the update processing according to the second embodiment, which is shown in 5 is the content of S201 to 203 and S205 essentially the same as from S101 to 103 and S105 the first embodiment (cf. 3rd ). On the other hand, at S204 Coordinates (hereinafter referred to as "positioning coordinates") based on the positioning position from the position identification section 65 read out and a driving locus RPm of the vehicle is determined. Points corresponding to the respective positioning coordinates on the driving locus RPm are calculated from a coordinate group of the calculated positions at S203 are calculated. At S204 For example, the coordinates of the calculated position, which are acquired at substantially the same time, and the position determination coordinates are linked with each other based on a time at which the coordinate information is obtained.

In the second embodiment described so far, the calibration coefficients of the gyro sensors 41 to 43 set so that the calculated position based on the vehicle speed information and the measurement value approaches the position determination position identified based on the position determination signal. As a result, gyro sensors can be unlike the prior art 41 to 43 be calibrated using the positioning signals received from the positioning satellites. The accuracy of the calibration can also be improved by improving the positioning accuracy.

(Third embodiment)

Likewise, in a third embodiment of the present disclosure, which is shown in 6 a function of a sensor calibration device by a display control device 300 realized. The display control device 300 is electrically direct or indirect with a HUD device 310 , a height sensor 340 and the like in addition to a GNSS receiver 20th , a map DB 30th , an in-vehicle LAN 50 and the like, which are substantially the same as those of the first embodiment.

An accelerometer 51 , a vehicle speed sensor 52 , a steering angle sensor 53 and the like are with an in-vehicle LAN 50 connected. The acceleration sensor 51 detects an acceleration in the longitudinal direction of the vehicle, which acts on the vehicle, and outputs a detection result to the in-vehicle LAN 50 out. The vehicle speed sensor 52 is, for example, a sensor for measuring a wheel speed and sends a measurement signal corresponding to the vehicle speed to the in-vehicle LAN 50 as vehicle speed information. The steering angle sensor 53 detects a steering angle of a steering system and sends the detection result to the in-vehicle LAN 50 out. The steering angle can be a steering angle or an actual steering angle of a steering wheel.

Similar to the HUD device 10th the first embodiment (cf. 1 ) uses the HUD device 310 an augmented reality (AR) display using a virtual image VI and a non-AR display in combination to present information to a driver. The HUD device 310 includes a projector 11 and a catoptric system 12th as a configuration for displaying a virtual image VI . The projector 111 represents the position of an original image based on the catoptric system 12th is projected based on the information of a position angle (inclination angle θ, see Expression 4) from the display control device 300 is obtained and maintains a state in which the AR displayed virtual image VI is correctly overlaid on an object.

The height sensor 340 is a sensor for detecting a vehicle height. The height sensor 340 can have at least one offset in the vertical direction (lifting) of a change in the position of the vehicle to capture. The height sensor 340 can, for example, be arranged on a vehicle exterior and installed on a left or right rear suspension. The height sensor 340 measures the sinking amount of a specific wheel that is displaced in the vertical direction relative to the body by the operation of a suspension arm suspended from a body. The height sensor 340 measures a relative distance between the body and the suspension arm and sequentially outputs a signal (for example a potential) of the measurement data to the display control device 300 out.

The height sensor 340 can be provided in several front, rear, left and right wheel suspensions of the vehicle. The measurement data of the height sensor 340 can by the display control device 300 through the in-vehicle LAN 50 can be obtained.

The display control device 300 includes a control circuit 60 , a permanent memory 60a , an input / output interface and the like, which are substantially the same as in the first embodiment. The permanent memory 60a the first embodiment also stores a sensor calibration program for calibrating an output of the height sensor 340 in addition to a display control program for controlling the display of the virtual image VI .

The control circuit 60 has functional blocks like a display control section 71 and a position calculation section 372 by executing the display control program. The control circuit 60 has functional blocks like a measurement acquisition section 361 , a steering angle information acquisition section 363 , a card acquisition section 364 and a calibration setting value setting section 366 in addition to a vehicle speed acquisition section 62 , an acceleration acquisition section 63 and a position identification section 65 by executing the sensor calibration program.

The location calculation section 72 calculates an inclination angle θ of the vehicle based on an output (for example, a voltage value) of the height sensor 340 by the measurement acquisition section 361 is obtained. The location calculation section 372 calibrates a raw output (potential V) of the height sensor 340 by a calibration expression shown in Expression 4 below. V0 in the calibration expression is an initial value of the height sensor output 340 . Either A as well as B in the calibration expression are calibration coefficients passed through the calibration value setting section 366 be determined.

$$\theta =a\cdot \left(V-V_0\right)+b$$

The measurement acquisition section 361 obtains a measured value of the vehicle offset (lift) based on the output of the height sensor 340 . The steering angle information acquisition section 363 obtains steering angle information that outputs a steering angle of the vehicle to the in-vehicle LAN 50 is issued. The map information acquisition section 364 obtained from a card DB 30th Information indicating a latitude, longitude and altitude of the road on which the vehicle is traveling and information indicating a transverse gradient (elevation) of the road surface.

The calibration value setting section 366 sets a calibration value coefficient (see Expression 4) to be applied to the measurement value of the elevation by the measurement value acquisition section 361 is obtained. In particular, a provisional value of the altitude information of the own vehicle can be calculated using the inclination angle θ and the vehicle speed. Such a calculated value has an error regarding a true value of the altitude information (cf. dashed line in 7 ) due to a change in weight balance of an upper portion of the suspension caused by variations in the number of occupants and a load, aging of the vehicle and the like. The calibration value setting section 366 updates a calibration coefficient to correct such an error and sets the calibration coefficient appropriate for the current vehicle. Accordingly, the position calculation section 372 calculate the vehicle attitude angle (inclination angle θ) with high accuracy by calibrating the error factor.

In particular, the calibration value setting section calculates 366 an own vehicle altitude RHc (see dashed line in 7 ) by a coordinate calculation expression, which is shown in expression 5 below. The own vehicle altitude RHc is obtained by connecting the coordinates of the calculated positions, which are calculated in time series based on the vehicle speed information and the measured value.

In the following coordinate calculation expression, v is a running speed of the vehicle, which is indicated by the vehicle speed information. Further, (z _i ) is a coordinate indicating an i-th calculated position in the calibration section and (z _{i + 1} ) indicating an (i + 1) -th calculated position. The inclination angle θ is a position angle based on a calibration expression (see Expression 4), in which a pre-calibration coefficient or a temporary calibration coefficient is specified. $${\mathrm{e.g.}}_{i+1}=v\text{cos}\theta {\text{+ z}}_i$$

Furthermore, the calibration value setting section sets 366 an own vehicle altitude RHm (see a solid line in 7 ) based on the positioning position and the map data. The calibration value setting section 366 assumes that the own vehicle altitude RHm is a true value based on the map data. Then the calibration value setting section calculates 366 a calibration coefficient such that the vehicle's altitude RHc , which is calculated according to the measured value, the vehicle's altitude RHm based on the map data approaches (this overlaps), that is, an error of the vehicle height RTc regarding the vehicle's altitude RHm is minimized.

In particular, the calibration value setting section sets 366 a pair of coordinate information pieces, which are estimated to indicate the vehicle height at the same time, from the respective vehicle height positions RHm and RHc firmly. The calibration value setting section 366 searches for a minimum value of the objective function shown in Expression 6 below. In the objective function there is an error norm between the coordinates (z ^ _i ) of the reference position on the vehicle height RHm and the coordinates (z _i ) of the calculated position on the vehicle height RHc calculated for the respective pairs of combined coordinates. The calibration value setting section 366 looks for a calibration coefficient that minimizes the sum of error norms by iterative calculation using a gradient method. "N" is the number of pieces of data used for calibration. $$\text{min}\left({\displaystyle \sum _{i=0}^n\sqrt{{\left({\widehat{\mathrm{e.g.}}}_i-{\mathrm{e.g.}}_i\right)}^{\mathrm{2nd}}}}\right)$$

Next, the update processing according to the third embodiment is carried out continuously by the display control device 300 is executed in detail with reference to 6 based on 8th and 9 described. The update processing performed in 8th is shown by the control circuit 16 based on switching the ignition to an ON state and repeats until the ignition is turned off, similar to the first embodiment and the like.

In S310 become the measurement value based on the output of the height sensor 340 and acquires the vehicle speed information and the processing goes along S302 away. At S302 are among the measured values at S301 the measurement values, which can cause a large error in the calibration coefficient, are excluded from an object to be used by the data selection processing performed in a subprocess in FIG 9 and the data to be used to set the calibration coefficient are selected.

At S321 In the data selection processing, acceleration information is obtained during a period or a time when the measured value is measured. It is then determined whether an absolute value of the acceleration occurring in the vehicle is a limit value D exceeds. Is at S321 determines that the absolute value of the acceleration is equal to or less than the limit D processing is included S323 away. On the other hand, if it is determined that the absolute value of the acceleration is the limit D processing is included S322 away. At S322 becomes the measured value during a period in which the absolute value of the acceleration exceeds the limit D exceeds, excluded from the object used to set the calibration coefficient, and the processing goes along S323 away. As described above, data during acceleration and deceleration are excluded from the object to be used.

At S323 information about the elevation of the road surface while driving is obtained. Then it is determined whether the absolute value of the cant is a limit E exceeds. If at S323 it is determined that the absolute value of the superelevation is equal to or less than the limit value E processing is included S325 away. On the other hand, if it is determined that the absolute value of the cant is the limit E processing is included S324 away. At S324 becomes the measured value in the period in which the absolute value of the cant exceeds the limit E exceeds, excluded from the object to be used to set the calibration coefficient, and processing goes along S325 away.

At S325 the vehicle speed information and the steering angle information are obtained, and a magnitude of a centrifugal force acting on the vehicle is estimated. It is then determined whether the absolute value of the estimated centrifugal force is a limit F exceeds. Is at S325 determines that the absolute value of the centrifugal force is equal to or less than the limit F processing is included S327 away. On the other hand, if it is determined that the absolute value of the centrifugal force is the limit F processing is included S326 away. In S326 is the measured value in the period in which the absolute value of the centrifugal force is the limit F exceeds, excluded from the object to be used to set the calibration coefficient, and processing goes along S327 away.

With the processing of S323 to S326 As described above, the data is excluded from the object to be used during cornering.

At S327 a variance value of the coordinates of the calculated position in a specific period is calculated and it is determined whether the variance value is a limit G exceeds. Is at S327 determines that the variance value is equal to or less than the limit G processing is included S329 away. On the other hand, if it is determined that the variance value is the limit G processing is included S328 away. At S328 becomes the measurement in the period in which the variance value is the limit G exceeds, excluded from the object used to set the calibration coefficient, and the processing goes along S329 away.

In S329 the longitudinal gradient of the road surface while driving is calculated according to latitude, longitude and altitude information given by the map data, and it is determined whether an absolute value of the longitudinal gradient is a limit H exceeds. Is at S329 determines that the absolute value of the longitudinal gradient is equal to or less than the limit H processing is reversed S303 the update processing (main processing). On the other hand, if at S329 it is determined that the absolute value of the longitudinal gradient is the limit H processing is included S330 away. At S330 becomes the measurement value in the period in which the absolute value of the longitudinal gradient is the limit H exceeds, excluded from the object used to set the calibration coefficient, and processing returns S303 the main processing back in 8th is shown. As described above, the data is excluded from the object to be used in the period in which the change in position associated with an ascent and a descent is recognizable.

At S303 becomes the pre-calibration own vehicle altitude RHc calculated based on the measured value and the processing moves along S304 away. At S304 becomes the own vehicle altitude RHm calculated based on the map data. Then the coordinates closest to the point (coordinates) corresponding to the individual coordinates on the own vehicle altitude RHm selected from a coordinate group of the calculated positions, which at S303 be calculated, and the processing goes along S305 away. At S305 become the calibration coefficients a and b of the calibration expression (cf. Expression 4) calculated in such a way that an error between the calculated position and the reference position which are linked to one another at S304 is minimized, and the update processing is completed once.

In the third embodiment described so far, the calculated position for the altitude is obtained by combining the measurement value based on the output of the altitude sensor 340 and the vehicle speed information obtained. If the calibration coefficient is set so that the calculated position approaches the reference position, the height sensor can 340 be calibrated using the altitude information.

According to the determination of the calibration coefficient as described above, since the accuracy of the position measurement based on the measured value of the height sensor 340 is improved, the display control section 71 the virtual image VI move with high accuracy according to a change in the position of the vehicle. Accordingly, the display control device 300 exactly the virtual image VI overlay the object in the driver's view.

Further, as in the third embodiment, high accuracy in the reference position, which is set using the altitude information included in the map data, be ensured. Accordingly, the accuracy of the calculated calibration coefficient and hence the accuracy of the inclination angle to which the calibration coefficient is applied can be maintained at a high level.

In this example, the measured value of the height sensor 340 obtained while the vehicle is traveling on a curve includes not only a component caused by a change in altitude, but also a component caused by a roll change associated with driving on the curve. Accordingly, in the third embodiment, the measured value that is measured during cornering is excluded from the object that is used to set the calibration coefficient. In particular, it is determined whether the measured value is to be used, based on information such as the steering angle and the corresponding speed of the vehicle and the cant. According to the above processing, an influence of the roll change that inevitably occurs when a one-way offset sensor is used can be reduced, and hence the accuracy of the calibration coefficient can be maintained at a high level.

Further, in a scene in which the gradient of the road is large while driving, a component caused by the change in inclination may be in the measured value of the height sensor 340 be included. Accordingly, in the third embodiment, the measured value becomes the period in which the longitudinal gradient of the road surface becomes the limit value H not used to set the calibration coefficient. According to the above processing, since the influence of changing the inclination of the vehicle can be reduced, the accuracy of the calibration coefficient can be maintained at a high level.

In the third embodiment, the height sensor corresponds 340 a "position sensor", the map information acquisition section 364 corresponds to a "altitude information obtaining section" and the display control device 300 corresponds to a "sensor calibration device".

Fourth Embodiment

When setting a calibration coefficient according to a fourth embodiment, instead of coordinates of an altitude indicated by the three-dimensional map data, coordinates of an altitude indicated by a positioning signal are used as a reference position. A calibration value setting section 366 who in 6 is shown, calculates an own vehicle altitude RHc (see. 7 ) of a vehicle by the same coordinate calculation expression (see Expression 5) as in the third embodiment. On the other hand, the calibration value setting section sets 366 an own vehicle altitude RHm (see. 7 ) in a driving locus of the vehicle by processing for connecting position determination positions by a position identification section 65 be identified in time series. The calibration value setting section 366 assumes that the own vehicle altitude RHm is a true value based on the position determination signal, and calculates calibration coefficients a and b (see Expression 4), so that an error between the calculated vehicle height RHc and the vehicle height RHm is minimized based on the positioning signal.

In the fourth embodiment described so far, a calibration coefficient of a height sensor becomes similar to the third embodiment 340 set such that the calculated position based on the vehicle speed information and the measured value approaches a reference position based on the position determination signal. As a result, accuracy of an inclination angle can be obtained using the measurement value of the height sensor 340 and a virtual image overlay accuracy VI to be maintained at a high level.

(Further embodiments)

Although several embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be applied to different embodiments and combinations within a range that does not depart from the spirit of the present disclosure.

In data selection processing (cf. 4th ) According to the embodiment described above, the measured values, which can reduce the accuracy of the calibration coefficient by successively carrying out several determinations, are excluded from the object to be used. The limit, used for the selection of such data can be appropriately set to a value that can ensure the accuracy of the calibration coefficient according to the specification information such as a weight of the vehicle and a wheel base, an assumed road environment and the like. Furthermore, the selection of data by the data selection processing need not be carried out. Furthermore, the content of the data selection processing can be changed appropriately.

(Modification 1)

For example, in data selection processing according to modification 1, the data determined in 10th is shown, the calibration value setting section whether a change range of the vehicle speed is less than or equal to a limit value ( S521 ). Then, data in a period in which a change range of the vehicle speed exceeds a limit value, such as during acceleration and deceleration in a start scene and a stop scene, are excluded from the object to be used for calculating the calibration coefficient ( S522 ). Accordingly, the calibration value setting section can set the calibration coefficient by selectively using only the measurement value whose traveling speed falls within the limit value that defines a constant change range for constant time.

(Modification 2)

In a data selection processing according to modification 2, which in 11 is shown, the calibration value setting section determines whether a time-derived value of the calculated position is equal to or larger than a limit value ( S523 ). The time-derived value is, for example, an amount of change per sampling cycle. Data in a period in which the time-derived value exceeds the limit, such as a time in which data pass irregularities, is excluded from the object to be used for calculating the calibration coefficient ( S524 ). As described above, the calibration value setting section can set the calibration coefficient by selectively using only the measurement value in a period in which a time-derived value is small.

(Modification 3)

In a data selection processing according to modification 3, which in 12th the calibration value setting section determines whether a variance value in a specified period is less than or equal to a limit value ( S525 ). Then, data in the period in which the variance value exceeds the limit value, such as a period in which the position of the vehicle changes greatly, is excluded from an object used for calculating the calibration coefficient S526 ). As described above, the calibration value setting section can set the calibration coefficient by selectively using only the measurement value in the period in which the variance value is small.

(Modification 4)

In the above-described embodiment, the attitude angles of the inclination axis, the roll axis and the yaw axis can be calibrated using the three-dimensional map data. However, the sensor section to be calibrated can be changed appropriately. For example, the measured value acquisition section according to modification 4 obtains the measured value for the yaw angle of the vehicle based on the output from the sensor section and does not obtain the measured values for the inclination angle and the roll angle. On the other hand, the map information acquisition section acquires two-dimensional map data including latitude and longitude information. The calibration value setting section may calculate the coordinates of the calculated position of only latitude and longitude based on the vehicle speed information and the measured value of the yaw angle. In other words, the calibration value setting section may have a two-dimensional driving locus RPc based on the calculated position and a two-dimensional driving locus RPm based on the map data. Accordingly, the correction coefficient is similar to the first embodiment, so that the driving locus RPc the driving locomotive RPm overlapped, searched so that the calibration value setting section can perform the yaw angle calibration using the two-dimensional map data. The yaw angle can be calibrated using only latitude and longitude information in the three-dimensional map data.

In the above-described embodiment, the processing for calibrating the gyro sensor to measure the values indicating the inclination, roll and yaw of the vehicle has been described. However, the position sensor to be calibrated is not limited to a gyro sensor. For example the acceleration sensor can be a position sensor to be calibrated. The sensor section may be a so-called six-axis sensor including an acceleration sensor for measuring acceleration in one direction along the three axes in addition to three gyro sensors for measuring angular velocities of the three axes. Further, in addition to the map data, the positioning information, and the like, conventional information such as the ambient temperature around the sensor section can also be used to calculate the calibration coefficient.

In the above-described embodiment, the map data is set as a true value and the calibration coefficient is set. In the second embodiment described above, the calibration coefficient with the position determination position is set as the true value. The processing described above can be combined with each other. For example, a reception state determination section for determining whether a reception state of the satellite signal is excellent is provided, and if it is determined that the accuracy of the position determination position is ensured, the calibration coefficient is set with the position determination signal as the true value. On the other hand, if it is determined that the accuracy of the position determination signal is not ensured, the calibration coefficient with the map data is set as the true value. Alternatively, an accuracy determination section for determining the accuracy of the map data is provided, and if it is determined that the accuracy of the map data is ensured, a calibration coefficient with the map data is set as the true value. On the other hand, if it is determined that the accuracy of the map data is not ensured, the calibration coefficient with the positioning signal is set as the true value.

In the first embodiment and the like, an actuator control section and an actuator are provided to maintain a state in which virtual image is correctly superimposed on an object. However, unlike the third embodiment, the setting of the display position of the virtual image does not have to be performed by hardware. In other words, the actuator control section and the actuator can be omitted. In the above configuration described above, the adjustment of the display position of the virtual image is carried out by adjusting the image data drawn by the display control section, specifically the position adjustment of an original image that is formed as the virtual image. As described above, the state in which the virtual image is correctly superimposed on the object can only be maintained by software processing. Alternatively, a state in which the virtual image is correctly superimposed on the object can only be maintained by the actuator control section and the actuator.

(Modification 5)

In modification 5, which is a modification of the third embodiment, the altitude information is obtained based on the gradient value. In particular, the control circuit of modification 5 is provided with a gradient value calculation section. The gradient value calculation section estimates the value (gradient value) of the road surface gradient (longitudinal gradient) from the response of the vehicle speed or acceleration to a tire driving force such as an accelerator opening degree and a brake hydraulic pressure with reference to an estimated weight of the vehicle. The altitude information acquiring section may acquire the altitude information serving as the reference position based on the gradient value and the vehicle speed information. In modification 5, as described above, even if the control circuit does not have the map information acquisition section and the position identification section, in other words, even if the map DB and the GNNS receiver are not mounted on the vehicle, the calibration value setting section can update the calibration coefficient.

In the third embodiment, the height sensor for measuring the offset in the vertical direction is exemplified as a unidirectional offset sensor. However, the update processing of the calibration value according to the present disclosure is applicable not only to the offset sensor in the vertical direction, but also to an offset sensor that measures an offset in any direction. In particular, if the measurement value of the displacement sensor is converted to the displacement amount in the vertical direction using the design value of the mounting angle of the displacement sensor to the vehicle, the same handling as that for the height sensor can be performed.

Furthermore, as the pseudo offset sensor, an acceleration sensor that can detect an acceleration component in the vertical direction can be used. When the calculation processing for integrating the measured values of the acceleration sensor twice as the offset amount in vertical direction, the acceleration sensor can be handled in the same way as the height sensor.

In the above-described embodiment, in order to avoid an error increase due to the influence of the roughness and the level difference of the road surface, the measurement value including the influence of the roughness and the level difference of the road surface is excluded from the object to be used for the calibration coefficient with which Use of information such as a variance value of the measured value or a time difference of the measured value in order to avoid the increase in errors due to the influence of the roughness and the difference in level of the road surface, which are not included in the map data. The occurrence of such roughness and the level difference on the road surface can be estimated, for example, based on the frequency of the measured value in addition to the variance value and the time difference.

Furthermore, in the third embodiment, in order to avoid an increase in error due to the influence of the roll angle component during cornering, the use and non-use of the measured value are classified based on the magnitude of the centrifugal force. For example, instead of the centrifugal force, the calibration value setting section may select to use or not to use the measurement value based on the magnitude of the steering angle, for example, to remove the roll angle component.

The combination of the multiple exclusion conditions described in the embodiment and the modification can be appropriately changed. Furthermore, the exclusion condition does not have to be set. In addition, a specific value of the limit value can be changed appropriately.

For example, in the three embodiments described above, limit values are set as exclusion conditions for both the centrifugal force and the superelevation, and the measured values for which it is estimated that they contain essentially no roll angle components in the two determinations are used selectively. However, in order to ensure an available measurement value, the calibration value setting section may, for example, perform filter processing for summing the magnitude of the roll angle based on the centrifugal force and the magnitude of the elevation and for excluding the measurement value in a period in which the summed value is a limit value based on the comparison between the summed value and exceeds the limit.

Furthermore, if the offset sensor is provided in the plurality of wheel suspensions, the exclusion condition for excluding the measurement value can be relaxed. For example, processing for forming the mean value of the measured values of the plurality of height sensors is carried out, so that the condition of the rough road surface and the measured value during cornering can be used to calculate the calibration coefficient. Further, the amount of data of the measurement value used for the calculation of the calibration coefficient can be increased while avoiding the influence of the road surface irregularities by processing or the like to exclude only the measurement value showing a single change. According to the processing described above, the expansion of the calibration section can be carried out.

In calculating the calibration coefficient, the calibration value setting section according to the above embodiment calculates a value at which the error between the driving locus and the own vehicle altitude is minimal by the gradient method. However, solving the minimization problem by searching for the calibration coefficient is not limited to the gradient method. For example, when a range of the calibration coefficient (calibration parameter) is narrowed to a certain degree, the calibration value setting section can obtain the minimum value by the total number inspection.

Further, if the calculated value (calculated position) of the displacement sensor differs greatly from the true value (reference position) before the calibration, the minimum value cannot be searched by the gradient method or the like. In this case, the calibration value setting section normalizes a series of calculated values so that the maximum value of the calculated values of the offset sensor before the calibration coincides with a maximum value of the true values. In this way, when the normalized calculated value is used, the calibration value setting section can search for the minimum value.

The function of the sensor calibration device can be realized by a configuration different from that of the display control device 100 differs. For example, a Display devices such as an instrument cluster and a HUD device function as a sensor calibration device by executing a sensor calibration program by a control circuit. Furthermore, the control circuit of the autonomous driving ECU mounted on the vehicle can function as a processor that executes the sensor calibration method of the present disclosure based on the sensor calibration program. Alternatively, a plurality of control circuits such as a display control device, a display device, and an ECU for autonomous driving can perform distributed processing of calculations for sensor calibration. In addition, various non-volatile, tangible storage media (non-volatile, tangible storage medium), such as flash memories and hard disks, can be used as read-only memories for storing sensor calibration programs and the like, which are to be executed by the processor.

In the above embodiment, the calibration value of the position sensor is set using high-precision map information as a reference. However, high precision map information is not generated for all roads and only map information with insufficient accuracy can exist. In this way, map information can be corrected with insufficient accuracy based on the output of the position sensor. In other words, the map information can be updated such that the driving locus RPm (see. 2A and 2 B) , which is identified from the map information, the driving locus RPc (see. 2A and 2 B) is superimposed, which is calculated based on the output of the position sensor and the driving speed. Such a technical idea is added below.

A map correcting device for correcting map information while a vehicle is traveling, the map correcting device including a measurement value acquisition section that obtains a measurement value of a position of the vehicle based on an output of a position sensor fixed to the vehicle, a vehicle speed acquisition section that acquires vehicle speed information that corresponds to a vehicle speed of the vehicle, a map information acquisition section that acquires map information of a road on which the vehicle is traveling and a map update section that updates position information so that position information that defines a position on the road by the map information matches a calculated position of the vehicle , which is calculated based on the vehicle speed information and the measured value.

According to the configuration described above, even if there is only map information with insufficient accuracy, the accuracy of the position information of the map information can be improved by the running of the vehicle. In addition, for example, if there is information indicating the accuracy of the map information, the information as the true value can be switched between the position information and the calculated information. In particular, when high-precision map information is obtained, information indicated by the map information is regarded as a true value and set as a reference position. Then, the calibration value setting section sets the calibration value of the position sensor by comparing the calculated position with the reference position based on the map information. On the other hand, if the map information is obtained with low accuracy, the calculated position is set as the true value based on the measured value of the position sensor. Then, the map update section performs processing for matching the road position indicated in the map information with the calculated position, thereby improving the accuracy of the map.

The flowcharts or the processing of the flowcharts described in the present disclosure are configured by multiple sections (or steps), and each section is, for example, as S101 represents. Furthermore, each section can be divided into several subsections, while several sections can be combined into one section. In addition, each section configured in this way can be referred to as a circuit, device, module, or means.

Likewise, each or a combination of the plurality of sections can be (i) a section of software in combination with a hardware section (e.g. a computer) and (ii) a section of hardware (e.g. an integrated circuit, a wired logic circuit) with or without the functionality of the associated device. Furthermore, the hardware section can be configured within the microcomputer.

Although the present disclosure has been described in accordance with the examples, it can be seen that the present disclosure is not limited to such examples or structures. The present Disclosure covers various modifications and variations within the scope of equivalents. In addition, different combinations and configurations, as well as other combinations and configurations that include a single element, more or less elements, are within the scope and spirit of the present disclosure.

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• JP 2017139339 [0001]
• JP 2018116304 [0001]
• JP 2009025012 A [0004]

Claims (23)

Sensor calibration device for calibrating an output of a position sensor (41 to 43) for detecting a position of a vehicle, the sensor calibration device comprising: a measurement value acquisition section (61) that acquires a measurement value of the position of the vehicle based on the output of the position sensor; a vehicle speed acquisition section (62) that acquires vehicle speed information indicating a running speed of the vehicle; a map information acquisition section (64) that acquires map information on a road on which the vehicle is traveling; and a calibration value setting section (66) that sets a calibration value that is applied to the measurement value to cause a calculated position of the vehicle calculated based on the vehicle speed information and the measurement value to approach a reference position specified in the map information is. Sensor calibration device according to Claim 1 wherein the measurement value acquisition section acquires the measurement values indicating an inclination, roll and yaw of the vehicle based on the output of the position sensor, and the map information acquisition section acquires three-dimensional map information including information about latitude, longitude and altitude. Sensor calibration device according to Claim 1 , wherein the measurement value acquisition section acquires the measurement value indicating a yaw of the vehicle based on the output of the position sensor, and the map information acquisition section acquires two-dimensional map information including information about latitude and longitude. Sensor calibration device according to one of the Claims 1 to 2nd wherein the calibration value setting section selects the calculated position corresponding to the reference position and searches for the calibration value to minimize an error between the selected calculated position and the reference position. Sensor calibration device for calibrating an output of a position sensor (41 to 43) for detecting a position of a vehicle, the sensor calibration device comprising: a measurement value acquisition section (61) that acquires a measurement value of the position of the vehicle based on the output of the position sensor; a vehicle speed acquisition section (62) that acquires vehicle speed information indicating a running speed of the vehicle; a position identification section (65) that identifies a position determination position of the vehicle based on a position determination signal received from a position determination satellite; and a calibration value setting section (66) that sets a calibration value that is applied to the measurement value to cause a calculated position of the vehicle calculated based on the vehicle speed information and the measurement value to approach the position determination position identified by the position identification section is. A sensor calibration device for calibrating an output of a position sensor (340) for detecting an offset of a vehicle, the sensor calibration device comprising: a measurement value acquisition section (361) that acquires a measurement value of the displacement of the vehicle based on the output of the position sensor; a vehicle speed acquisition section (62) acquires vehicle speed information indicating a running speed of the vehicle; an altitude information acquisition section (364) that acquires altitude information about a road on which the vehicle is traveling; and a calibration value setting section (366) that sets a calibration value applied to the measurement value to cause a calculated position of the vehicle calculated based on the vehicle speed information and the measurement value to approach a reference position specified in the altitude information is. Calibration device according to Claim 6 , in which the altitude information acquisition section acquires map information including the altitude information, and the calibration value setting section sets the calibration value to cause the calculated position to approach the reference position using the altitude information based on the map information. Sensor calibration device according to Claim 6 , wherein the altitude information acquisition section acquires the altitude information based on a positioning signal received from a positioning satellite, and the calibration value setting section sets the calibration value to cause the calculated position to approach the reference position using the altitude information based on the positioning signal. Sensor calibration device according to Claim 6 wherein the altitude information acquisition section acquires the altitude information based on a gradient value of a road surface of the road on which the vehicle is traveling, and the calibration value setting section sets the calibration value to cause the calculated position to approach the reference position using the altitude information based on the Gradient value. Sensor calibration device according to one of the Claims 6 to 9 , wherein the calibration value setting section sets the calibration value excluding the measurement value measured by the position sensor while the vehicle is turning. Sensor calibration device according to Claim 10 wherein the calibration value setting section excludes the measurement value from an object used to set the calibration value in a period when a steering angle of the vehicle or a centrifugal force acting on the vehicle exceeds a limit value. Sensor calibration device according to Claim 10 or 11 wherein the calibration value setting section excludes the measurement value from an object used for setting the calibration value in a period in which a transverse gradient of a road surface of the road on which the vehicle is traveling exceeds a limit value. Sensor calibration device according to one of the Claims 10 to 12th wherein the calibration value setting section excludes the measurement value from an object used for setting the calibration value in a period in which a longitudinal gradient of a road surface of the road on which the vehicle is traveling exceeds a limit value. Sensor calibration device according to one of the Claims 1 to 13 , wherein the calibration value setting section sets the calibration value excluding the measurement value measured by the position sensor while the vehicle is accelerating and decelerating. Sensor calibration device according to Claim 14 wherein the calibration value setting section sets the calibration value using the measurement value in a period in which a change range of the vehicle speed indicated by the vehicle speed information falls within a limit value. Sensor calibration device according to Claim 14 or 15 further comprising: an acceleration acquiring section (63) acquiring acceleration information indicating an acceleration of the vehicle, the calibration value setting section excluding an object to be used for setting the calibration value in a period in which an absolute value of the acceleration specified by the acceleration information exceeds a limit. Calibration device according to one of the Claims 1 to 16 wherein the calibration value setting section sets the calibration value excluding the measurement value measured by the position sensor in a period in which the vehicle passes an unevenness of a road surface. Sensor calibration device according to Claim 17 , wherein the calibration value setting section sets a calibration value excluding the measurement value in a period in which a time-derived value of the calculated position exceeds a limit value. Sensor calibration device according to Claim 17 or 18th , wherein the calibration value setting section sets the calibration value excluding the measurement value in a period in which a difference value of the calculated position exceeds a limit value over time. Sensor calibration device according to one of the Claims 1 to 19th , wherein the calibration value setting section sets the calibration value excluding the measurement value in a period in which a variance value of the calculated position exceeds a limit value. A sensor calibration program for calibrating an output of a position sensor (41 to 43) to detect a position of a vehicle, the sensor calibration program causing at least one processor (60) to function as: a measurement value acquisition section (61) that acquires a measurement value of the position of the vehicle based on the output of the position sensor; a vehicle speed acquisition section (62) that acquires vehicle speed information indicating a running speed of the vehicle; a map information acquisition section (64) that acquires map information of a road on which the vehicle is traveling; and a calibration value setting section (66) that sets a calibration value that is applied to the measurement value to cause a calculated position of the vehicle calculated based on the vehicle speed information and the measurement value to approach a reference position specified in the map information is. A sensor calibration program for calibrating an output of a position sensor (41 to 43) to detect a position of a vehicle, the sensor calibration program causing at least one processor (60) to function as: a measurement value acquisition section (61) that acquires a measurement value of the position of the vehicle based on the output of the position sensor; a vehicle speed acquisition section (62) that acquires vehicle speed information indicating a running speed of the vehicle; a position identification section (65) that identifies a position determination position of the vehicle based on a position determination signal received from a satellite; and a calibration value setting section (66) that sets a calibration value that is applied to the measurement value to cause a calculated position of the vehicle calculated based on the vehicle speed information and the measurement value to approach the position determination position identified by the position identification section is. A sensor calibration program for calibrating an output of a position sensor (340) to detect an offset of a vehicle, the sensor calibration program causing at least one processor (60) to function as: a measurement value acquisition section (361) that acquires a measurement value of an offset of the vehicle based on the output of the position sensor; a vehicle speed acquisition section (62) acquires vehicle speed information indicating a running speed of the vehicle; an altitude information acquisition section (364) that acquires altitude information about a road on which the vehicle is traveling; and a calibration value setting section (366) that sets a calibration value that is applied to the measurement value to cause a calculated position of the vehicle calculated based on the vehicle speed information and the measurement value to approach a reference position indicated in the altitude information is.

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